"The Syrian government has requested the Secretary-General of the United Nations to form a specialised, independent and a neutral, technical mission to investigate the use by the terrorist groups operating in Syria of chemical weapons yesterday against civilians," Ja'afari told reporters.

Syria's government and rebels accused each other of launching the deadly chemical attack on Tuesday, but U.S. and European officials say there is no evidence to suggest there was such an attack. If confirmed it would be the first use of such weapons in the 2-year-old conflict.

U.N. spokesman Martin Nesirky said the United Nations had not received a formal request from Syria for an investigation and would respond once its receives one.